A cenote is a natural phenomenon, a sinkhole in the Earth’s surface. The Yucatan Peninsula in Mexico has an estimated 7,000 cenotes because it is primarily made up of porous limestone. For millions of years, rainfall slowly ate away at the limestone and a huge system of underground caves and caverns was formed. Many filled with water from rain or from the underground water table. When the roof of a water filled cave collapses, a cenote is born. The water found in a cenote may be fresh water, salt water, or both. Structurally it may be completely open, like a lake, almost completely closed with just a small opening at the top, or somewhere in between.

Potoos (family Nyctibiidae) are a group of near passerine birds related to the nightjars and frogmouths. They are sometimes called Poor-me-ones, after their haunting calls. There are seven species in one genus, Nyctibius, in tropical Central and South America.
These are nocturnal insectivores which lack the bristles around the mouth found in the true nightjars. They hunt from a perch like a shrike or flycatcher. During the day they perch upright on tree stumps, camouflaged to look like part of the stump. The single spotted egg is laid directly on the top of a stump.

This deviantART artist Wood-Splitter-Lee creates her own animal sculptures without the use of any dead carcasses. The basis of each animal's shape is made out of materials such as wood, clay and chicken wire, and is then wrapped up in a soft padding. On top of that, she adds imitation fur that she hand dyes and as many details and decorative elements as she sees fit. The result are truly one-of-a-kind fantasy creatures.

The British Wildlife Photography Awards winners have been revealed, with Lee Acaster from Suffolk taking home the top prize for his shot of a Graylag Goose in London. Acaster, who received £5,000, photographed the animal against an ominous London skyline, with The Shard clearly visible in the background. Here: “Urban Tourist (Graylag Goose)”. Urban category and overall winner. (Photo by Lee Acaster/British Wildlife Photography Awards 2014)

Kyaiktiyo, Burma, 1978. The Golden Rock at Shwe Pyi Daw (the Golden Country), the Buddhist holy place. Hiroji Kubota writes: “I was desperate to keep a distance from America for a while; luckily, I found Burma and its gentle and compassionate people. In the spring of 1978, on the top of the hill where I took this photo, I had two Leica bodies: the one with Tri-X and the other with Kodachrome 64. Soon after, I realised that the colour one looked very colourful and was more powerful. That was my decisive moment, to become a colour photographer”. (Photo by Hiroji Kubota/Magnum Photos)

Thorsten Mowes has a more intimate knowledge of the worlds most famous monuments than perhaps anyone else on the planet – because hes spent his entire career cleaning them. As a cultural cleaning expert with nearly 25 years experience, he has been commissioned to make wonders all over the world shine like new – from the London Eye to Christ the Redeemer. The places he has been to, stood on top of, or even hung halfway down include Mount Rushmore and the Space Needle in America, the London Eye, the Statue of Christ in Brazil and the Forbidden City in China. Here: A man cleans a part of Mount Rushmore. (Photo by Caters News Agency)

Nguyen Manh Quan (top), 26, a civil servant, carries a girl using his throat area as he performs during a showcase of the traditional Thien Mon Dao kung fu at Du Xa Thuong village, southeast of Hanoi, Vietnam May 10, 2015. Thien Mon Dao, a traditional Vietnamese martial art, was formed by 18th century villagers in Du Xa Thuong village, who believed the art form could help improve health as well as fight against foreign invaders. There are currently about 3,000 practitioners including farmers, industry workers and state servants. These practitioners say they are able to bend metal against their bodies and carry heavy objects using their throats, eyes or tongues, as well as run across the surface of a river, according to Thien Mon Dao kung fu master Nguyen Khac Phan. (Photo by Reuters/Kham)

A photographer has shot this series of scenic selfies – scaling freezing mountain tops to snap himself in front of stunning scenery. Paul Zizkas breath-taking work features himself in front of beautiful backdrops such as shimmering lakes, snowy mountains and vibrant auroras. He has travelled to a number of different locations worldwide including Canada, New Zealand, Niue the South Pacific and French Polynesia. Explorer Paul, from Banff, Alberta, Canada, saw his selfies go viral early in 2014 – and has now unveiled his latest work. He said: I find that sometimes including a person in a landscape scene adds to the photograph – that it conveys a different story. Here: lake Minnewanka, Banff National Park, Alberta, Canada. (Photo by Paul Zizkas/Caters News)